Preferential adsorption of bovine serum albumin dimer onto polymer microspheres having a heterogeneous surface consisting of hydrophobic and hydrophilic parts

Abstract

The adsorption behaviors of bovine serum albumin (BSA) containing both dimeric and monomeric species onto polymer microspheres were examined using various h0mopolymers and poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres which were produced by the emulsifier-free (seeded) emulsion polymerization technique. The preferential adsorption of the BSA dimer was clearly observed in an optimum region of the surface hydrophilicities of the polymer microspheres. The preferential adsorption of the BSA dimer onto the composite polymer microspheres having heterogeneous surfaces consisting of hydrophiIic and hydrophobic parts was more marked than those onto the homopolymer and copolymer microspheres having homogeneous surfaces.

Electrospray–differential mobility analysis of bionanoparticles

“…Therefore one can conclude, that at least 88 for the proteins examined in this study, protein adsorption does not influence aggregate distributions measured at steady state by ES-DMA. Although, size distributions of different proteins in this study were obtained using differential mobility analyzer, these findings apply to other techniques that use ES for aerosolization of proteins as well (e.g.…”

“…To avoid the adverse effects of labeling, other "label-free" tools have been employed such as size exclusion chromatography [87,95,96], electrophoresis [128], ellipsometry [132,133], spectroscopy [134], surface plasmon resonance [101], quartz crystal microbalance [135], tensiometry [132], reflectrometry [136], shear rheology [125], surface force apparatus [137] and imaging techniques [138]. However, there are only a few reports where these tools have been employed on oligomers (monomers, dimers etc) of the same protein [87][88][89]. The objective of this section is to demonstrate that ES-DMA is one such tool that can be employed for routinely studying adsorption-desorption of heterogenous protein mixtures.…”

“…This effect has been observed in both stagnant [83,84] and low shear flow conditions (≈ 500 sec -1 , 225 sec -1 to 2700 sec -1 ) [85,86]. However, with a few exceptions, [87][88][89] there seems to be an overall lack of tools that can study adsorption-desorption of oligomers of same protein other than a few exceptions. Furthermore, it is common to label proteins while studying multi-protein systems or sequential adsorption [92][93][94] despite the fact that labeling may change conformational stability of proteins and also affect adsorption patterns [95][96][97].…”

“…The characterization methods employed can be broadly characterized into solution depletion, optical, spectroscopic, imaging and surface force measurement techniques [81,82]. Most of these techniques operate at stagnant conditions [83,84] or at low shear [85,86] (typically 10 2 sec -1 to 10 3 sec -1 ) and have only rarely [87][88][89] been used for studying competitive adsorption of protein oligomers (i.e. monomers, dimers, trimers etc.…”

Formation of Adsorbed Protein Layers

“…Although some changes in interaction may be the result of the self-assembly, reasonably similar species differing strongly in molecular weight may be investigated. Studies of this type have been performed, e.g., for human serum albumin (HSA), BSA, ␤-lactoglobulin, and insulin (2,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). For example, the adsorption of BSA monomers and dimers was investigated by Okubo et al, who found that the dimer adsorbs preferentially over the monomer at a number of surfaces and a range of protein concentrations (17).…”